Device for treating a strip of fabric

ABSTRACT

The treatment device includes a container for a treatment fluid, in which a drum around which the web loops rotates eccentrically. The drum is made up of axis-parallel, hollow, sealed rods and possesses a drum shaft structured as a hollow shaft, which together produce a buoyancy which makes up a significant part of the weight of the drum and the drum shaft. The drum is suspended at one end via stretchably elastic drive belts, and at the other end on tension springs, which catch the remaining weight. The drum shaft is eccentrically mounted on an eccentric shaft. The eccentric shaft is provided with equalization weights. All of the measures act together to allow low-vibration operation, towards the outside, of the treatment device.

BACKGROUND OF THE INVENTION

The invention relates to a treatment device for a continuously movingweb. The device has a machine frame and a container that is supported inthe machine frame to hold a treatment fluid and has a drum that canrotate in the container in the treatment fluid. This drum has acylindrical, fluid-permeable circumference, at the bottom of which theweb rests against the region which is immersed in the container, at alooping angle of at least, and further has a driven eccentric shaftwhich is rotationally mounted in fixed external bearings. Also providedis a drum shaft that carries the drum, eccentrically mounted on theeccentric shaft, structured as a hollow shaft, and surrounding theeccentric shaft, which is rotationally mounted at its ends on regions ofthe eccentric shaft that are eccentric to the axis of rotation of theeccentric shaft.

Such a treatment device is described in German Patent 11 13 201. Therotating eccentric shaft has regions eccentric to its axis of rotation,on which the drum shaft is mounted by means of roller bearings. As theeccentric shaft rotates, the drum shaft and therefore the drum supportedon it perform an eccentric movement. At the same time, the drum rotates,in which connection it can be entrained by the web, but also can itselfbe driven. The web surrounds the drum and is moved back and forth in thetreatment fluid contained in the container, as the drum performs itseccentric movement, perpendicular to the plane of the fluid, therebyresulting in an increased bath exchange and an improved treatmenteffect, particularly washing effect.

Because of the eccentric movement of the drum, strong vibrations occur,which made a special foundation necessary for the known device. Inaddition, the parts of the device were subject to significantalternating stresses over an extended period of time, which placedspecial demands on the material.

SUMMARY OF THE INVENTION

The invention is based on the task of reducing the vibration relatedproblems present in prior art devices of the type set forth above. Thepresent invention improves on existing designs by providing that thedrum shaft be suppported on the machine frame at both ends, an anelastically resilient manner, in a plane perpendicular to its axis.

In this way, the mounting of the drum shaft on the eccentric shaft canbe relieved of part of the weight of the drum, and the drum shaft can berelieved of part of the mass forces. The mass forces of the drum and thedrum shaft which are passed on to the eccentric shaft are passed on tothe machine stand, in damped manner. This already achieves a significantimprovement in the effects of vibrations.

In the preferred embodiment, the drum shaft is suspended on the machinestand in elastically resilient manner, i.e. the elastically resilientsupport is located above the drum shaft and is subject to tensilestress.

According to another important aspect of the invention, the hollowelements, namely the rods and the drum shaft, form buoyancy elementswhich can take over a significant part of the weight of the drum and thedrum shaft when the drum is immersed in the treatment fluid in itsoperating state.

The hollow rods are actually known from German Patent 44 13 871 C1, butthey deviate from the state of the art of the preamble with regard tothe mounting of the drum and the production of the eccentric movement.

In another aspect of the invention, if the drum has an endlessstretchably elastic pulling drive element, such as a belt or severalparallel round belts, this pulling drive element can simultaneouslyserve as an elastic support which catches at least part of the weight ofthe drum and the drum shaft.

The drive is provided at only one end of the drum. At the other end, theelastic support can be formed such that the drum shaft carries a pivotbearing at that end, which is supported on the machine frame via bysprings, particularly by tension springs.

Another aspect of the invention concerns the buoyancy volume and thestress on the stretchably elastic supports on the two ends of the drumshaft. The volume of the drum shaft and the rods which is immersed inthe treatment fluid is sized in such a way that at the typicaloperational immersion depth, the buoyancy is 70 to 90% of the weight ofthe drum and the drum shaft), while the remaining weight is carried bythe stretchably elastic pulling drive element at the one end and thesprings at the other end of the drum shaft. Hence, a significant part ofthe weight of the drum and the drum shaft are therefore equalized by thebuoyancy, while only a small part is to be caught by the stretchablyelastic support.

To reduce the development of vibrations, equalization masses areprovided at the eccentric shaft in the vicinity of the eccentricregions. (Such equalization masses on treatment devices of the type inquestion are known.)

A significant aspect of the present invention is the combination of theaforementioned characteristics, namely utilization of the buoyancy ofthe drum and the drum shaft, the elastically resilient support of thetwo ends of the drum shaft, and the equalization masses on the eccentricshaft. These characteristics, in combination, result in a device whichgives off hardly any significant vibrations to the environment inoperation, and in particular no longer requires a complicated, separatefoundation.

BRIEF DESCRIPTION OF THE DRAWING

The drawings illustrate one embodiment of the present invention, inwhich:

FIG. 1 shows a vertical cross-section through the device; and

FIG. 2 shows a cross-section along line II—II in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The treatment device, designated as a whole as 100 in FIG. 1, includes amachine frame 1 which possesses two side cheeks 1′, 1″ which lieparallel, upright, and opposite one another and are connected with oneanother by cross-beams 2, 3, 4. A container 5, open toward the top andapproximately U-shaped in cross-section, extends between side cheeks 1′,1″; it is supported by cross-beams 2, 3, 4 in the manner evident in FIG.2, and can be filled with a treatment fluid Fl, e.g. a washing fluid, upto filling level 6.

A drum, designated as a whole as 10, is mounted in container 5, and issupported on a drum shaft 15 structured as a hollow shaft. Thecircumference of drum 10 is made up of closely spaced, axis-parallelrods 11, which are structured as sealed pipes and are supported on drumshaft 15 on three carrier disks 12, 13, 14, which are perpendicular tothe axis. Rods 11 together form a cylindrical sheath surface, aroundwhich a web W is looped in the manner evident in FIG. 2. The loopingangle is approximately 3000 in the exemplary embodiment, i.e. the entirebottom part of web W rests on drum 10 and is thereby immersed intreatment fluid Fl. The large looping angle is brought about by twodeflection rollers 16, 17 which are arranged parallel to the drum axisand adjacent to one another, directly above drum 10. In the exemplaryembodiment, these are arranged symmetrically above drum 10. However, anarrangement displaced to the side is also possible. An asymmetricalarrangement can have an advantageous effect on the treatment process,because intimate contact between web W and drum 10 is achieved under theeffect of gravity, due to the weight of web 10, in the upper region ofthe drum, and therefore the exchange of bath in web W is increased.Above deflection rollers 16, 17, at a greater distance from one another,two additional deflection rollers 18, 19 are also provided in machineframe 1, via which web W is passed into and out of the device in thedirection of the arrow, and which can also be structured as spreadingrollers or devices.

Container 5 has essentially flat face walls 7, 8 at its ends located inthe axis direction of drum shaft 15, arranged close to frame cheeks 1′and 1″, through which ends 15′, 15″ of drum shaft 15 pass. Ends 15′, 15″reach into the region of frame cheeks 1′, 1″.

The passage locations of drum shaft 15 through face walls 7, 8 aresealed with seal arrangements 9, which are structured as axial faceseals in the exemplary embodiment, which permit a slight displacement ofdrum shaft 15 perpendicular to its axis, relative to face walls 7, 8.

Drum shaft 15 has an eccentric shaft 20 passing through it over itslength, which projects beyond drum shaft 15 at its ends, where it ismounted to rotate around an axis A, on fixed pivot bearings 21, 22affixed on the outside of frame cheeks 1′, 1″. A gear motor 23 serves todrive eccentric shaft 20.

Axially inside pivot bearings 21, 22, eccentric shaft 20 has cylindricalregions 24, 25 which are offset eccentrically in the same direction,opposite ends 20′, 20″ of eccentric shaft 20, as is indicated by thedouble axis line at the level of regions 24, 25.

Ends 15′, 15″ of drum shaft 15 are mounted to rotate on regions 24, 25,via pivot bearings 26, 27. Hence, if therefore eccentric shaft 20rotates relative to drum shaft 15, it performs an eccentric movementrelative to axis A of the eccentric shaft, i.e. drum 10 is displacedparallel to itself, by an amount which corresponds to the eccentricity,into container 5. In general, an eccentricity of up to severalmillimeters is involved.

Equalization masses 28 are affixed on the side opposite theeccentricity, axially adjacent to eccentric regions 24, 25 of eccentricshaft 20 and inside; they ensure mass equalization of rotating eccentricshaft 20.

Drum 10 with drum shaft 15 is also driven in rotation. For this purpose,end 15′ of drum shaft 15 bears a drive pulley 30, above which acorresponding drive pulley 31 is arranged, which is driven by a gearmotor 29, whose journal forms a fixed bearing 29′ for drive pulley 31.The drive is provided via endless, stretchably elastic pulling driveelements looped around drive pulleys 30, 31; in the exemplaryembodiment, these drive elements are chosen to be round belts 32 whichrun adjacent to one another. Round belts 32 are pre-stressed and exert acertain upwardly directed force on end 15′ of drum shaft 15,corresponding to part of the weight of drum 10 and drum shaft 15. Thispre-stress not only makes it possible to transfer the drive torque, butalso integrates pulling drive elements 32 into the vibration system,where they exert a damping effect.

On the opposite side, end 15″ of drum shaft 15 located there is alsosuspended resiliently, specifically by means of tension springs 33,which are fixed in place in the top region of frame cheek 1″ locatedthere, and on which a bearing ring 34 is suspended, which is mounted onend 15″ of drum shaft 15 via a ball bearing 35.

Drum 10 rotates relatively slowly compared with the speed of the web,i.e. at a speed on the order of 30 rpm at a web speed of 100 m/min, forexample. Eccentric shaft 20, on the other hand, rotates rather quickly,i.e. at 500 or 800 rpm. It therefore generates a vibrating movement ofdrum 10 perpendicular to its axis. This results in rather strongvibrations, which are to be equalized or damped within device 100, ifpossible. For this purpose, several of the developments described worktogether. Rods 11 and drum shaft 15 are hollow and sealed, so that notreatment fluid can penetrate into them. Drum 10 is immersed intreatment fluid Fl to such an extent, during operation, that it justlooks out at the top. At this immersion depth, rods 11 and drum 15develop a buoyancy that amounts to approximately 80% of the weight ofdrum 10 and drum shaft 15 (outside of the treatment fluid). Theremaining 20% of the weight is carried by the round belts 32 and springs33, so that the weight of drum 10 and drum shaft 15 is essentiallyequalized and there is no stress on bearings 26, 27.

Still another point is equalization weights 28, which equalize theeccentricity of regions 24, 25, and ensure smooth running of rapidlyrotating eccentric shaft 20.

Another point is the elastic suspension of drum shaft 15 on elements 32and 33, which provide damping of the vibrations caused by the eccentricmovement of drum shaft 15. The elastic stretchability of round belts 32also permits transfer of the drive force for drum 10 from a fixed drivepulley 31 to drive pulley 30 which moves back and forth in accordancewith the eccentricity.

As is evident from FIG. 2, spray nozzles 36, 37 can be provided oppositeone another on both sides of web W, in the region of deflection roller19 adjacent to the exit area. The entire top part of the treatmentdevice is surrounded by a sheet-metal housing 38 and a cover 39, inorder to avoid heat losses and to prevent the treatment fluid from beingsprayed out.

What is claimed is:
 1. A treatment device for treating a continuouslymoving web, comprising: a machine frame; a container supported in themachine frame, to hold a treatment fluid; a drum rotatably locatedwithin the container, so that it is largely immersed in the treatmentfluid, the drum having a cylindrical, fluid-permeable circumference, atthe bottom of which the web rests against a region of the drum which isimmersed in treatment fluid, the web wrapping about the drum with alooping angle of at least 270°; a driven eccentric shaft which is hollowand rotationally mounted in fixed external bearings; a drum shaft havinga first end and a second end, that carries the drum, eccentricallymounted on the eccentric shaft, and which surrounds the eccentric shaft,the drum shaft being rotationally mounted at its ends on regions of theeccentric shaft that are eccentric to the axis of rotation of theeccentric shaft; wherein the drum shaft is supported on the machineframe at both ends, in elastically resilient manner, in a planeperpendicular to its axis.
 2. The treatment device according to claim 1,wherein the fluid-permeable circumference of the drum is formed byaxis-parallel, hollow, sealed rods arranged closely adjacent to oneanother, and the hollow drum shaft is sealed to prevent the entry oftreatment fluid.
 3. The treatment device according to claim 2, whereinthe drum shaft carries a drive pulley at the first end, a correspondingdrive pulley, connected to rotate with a motor, is mounted in a fixedbearing above a drive pulley, in machine frame, and an endless,stretchably elastic pulling drive element loops around the two drivepulleys.
 4. The treatment device according to claim 3, wherein the drumshaft carries a ball bearing at the second end, and the ball bearing issupported on the machine frame via springs, in a plane perpendicular toits axis.
 5. The treatment device according to claim 4, wherein abearing ring is suspended on the machine frame on the springs.
 6. Thetreatment device according to claim 2, wherein the volume of the drumshaft and the rods which is immersed in the treatment fluid is sized insuch a way that at the immersion depth normal in operation, the buoyancyis 70 to 90% of the weight of the drum and the drum shaft, while theremaining weight is carried by a stretchably elastic pulling driveelement at the first end and springs at the second end of the drumshaft.
 7. The treatment device according to claim 1, wherein the drumshaft carries a drive pulley at the first end, a corresponding drivepulley, connected to rotate with a motor, is mounted in a fixed bearingabove a drive pulley, in the machine frame, and an endless, stretchablyelastic pulling drive element loops around the two drive pulleys.
 8. Thetreatment device according to claim 7, wherein the volume of the drumshaft and the rods which is immersed in the treatment fluid is sized insuch a way that at the immersion depth normal in operation, the buoyancyis 70 to 90% of the weight of the drum and the drum shaft, while theremaining weight is carried by the stretchably elastic pulling driveelement at the first end and springs at the second end of the drumshaft.
 9. The treatment device according to claim 8, whereinequalization masses to counteract the eccentricity of the eccentricshaft are provided on the eccentric shaft, close to eccentric regions.10. The treatment device according to claim 1, wherein equalizationmasses to counteract the eccentricity of the eccentric shaft areprovided on the eccentric shaft, close to eccentric regions.